Method and apparatus for the production of a fabric free of warp-wise running irregularities at a wave weaving loom



Jan. 9, 1968 H. FEND 3,362, METHOD AND APPARATUS FOR THE PRODUCTION OF AFABRIC FREE OF WARP-WISE RUNNING IRREGUIJARITIES AT A WAVE WEAVING LOOMFiled Aug. 23, 1965 2 Sheets-Sheet 1 H. FEND 3,362,436 FOR THEPRODUCTION OF A FABRIC Jan. 9, 1968 METHOD AND APPARATUS 2 Sheets-Sheet2 Filed Aug. 23, 1965 INVENTOR HEINRICH FEND i B ATTORNEYS United StatesPatent 3,362 436 METHOD AND APPARATUS FOR THE PRODUC- TION OF A FABRICFREE OF WARP-WISE RUNNING IRREGULARITIES AT A WAVE WEAV- ING LOOMHeinrich Feud, Uster, Zurich, Switzerland, assignor to Oerlikon-BuhrleHolding A.G., Zurich, Switzerland Filed Aug. 23, 1965, Ser. No. 481,471Claims priority, application Switzerland, Oct. 9, 1964, 13,145/ 64 15Claims. (Cl. 139-12) ABSTRACT OF THE DISCLOSURE The movement of the fellline in wave weaving looms is controlled so as to produce a fabric withthe warp-wise running irregularities removed. This is accomplished byproviding a stationary segment shaped deflecting member cooperating withthe cloth formed at the fell line and extending forwardly of the fellline. Such deflecting member has a convex guiding surface extending inthe direction of the warp. Cooperating therewith are stationaryadjustable convex guiding members. Also in order to reduce the weight ofthe guiding members such members in unloaded state may be bent so thatwhen loaded the curvature will be partially reduced.

The present invention has reference to an improved method of, andapparatus for, the production of fabrics free of warp-wise runningirregularities in a wave weaving loom.

During weaving upon conventional looms beating of each weft thread atthe fell of the cloth takes place, after insertion of such weft threadsimultaneously across the entire fabric width, by means of a reedextending across such fabric width. Due to such beating the fell line ofthe cloth is temporarily displaced forwards, the tension of the stillunwoven portion of the chain of warp threads forming the shedtemporarily increasing across the full weaving width, and the tension ofthe fabric extending from the fell line to the cloth beam temporarilyreducing, also across the entire cloth width. At this moment the fabricis advanced forwardly through a weft thread spacing. Upon return of thereed the tension of the unwoven warp portions and the fabric againbalances, whereby the fell line formed by the newly beaten Weft threadreturns to its former position.

In order to prevent the tension at the still unwoven warp portions frombecoming too great at the moment of beating and in order to reduce thedanger of rupture of the warp threads, it has already been proposed thatthe fell line of the departing fabric be permitted to pass over bothedges of a trough having a cross-section which widens in trapezoidalmanner towards the bottom, and for the fabric to pass between theseedges beneath a rod disposed in this trough, the diameter of which islarger than the mutual spacing of the aforementioned edges of thetrough.

Owing to the increased tension of the fabric during return of the reed,this rod is pulled towards the. walls of the trough which narrowstowards the top and is wedged therebetween, whereby the fabric isfixedly clamped so that it cannot move backwards any furthenThe unwovenwarp portions, the tension of which again assumes a value controlled bya regulating device, t-hus experience a small elongation during the nextbeating action of the reed and attain a smaller maximum tension thanwith free movement of the fell line of the cloth.

In wave weaving looms-that is, looms in which weft threads are insertedand beaten in a plurality of wave-like sheds of finite or limited widthsuccessively following one another across the weaving widthbeating ofeach weft 3,352,436 Patented Jan. 9, 1968 thread at the fell line of thefabric takes place, in each instance, directly after the insertion of asmall section of such weft thread at a corresponding section of thecloth width, by means of one of a plurality of juxtapositroned reedgroups moving forwardly and rearwardly in time-displaced cycles.Formation and changing of the sheds likewise occurs by means of aplurality of juxtapositioned harness groups working in displacedoperating cycles. As a result, differences in the tension of the warpthreads can appear from one harness group to the other and from one reedgroup to the other, which during beating results in differentdisplacements of the fell line with free displaceability of the fabric.Thus, in the finished fabric there appear stripes of differently wovengoods which extend in the direction of the warp, the width of whichsubstantially corresponds to that of the harness groups and reed groups.Such striped cloth is not desirable and, therefore, it is a primaryobjective of the present invention to prevent such.

Another more specific object of this invention is to provide an improvedmethod of, and apparatus for, weaving a fabric at a wave weaving loomwhich is substantially free of warp-wise running irregularities.

The previously mentioned known measure of permitt ng the fabric to passbeneath a clamping rod or bar located in a trough possessing across-section which narrows towards the top is not applicable for waveweaving looms since such a clamping rod extends across the full clothwidth and can only then function satisfactorily if each weft thread issimultaneously beaten along the entire length of the rod. However, itmust be remembered when weaving upon a wave weaving loom that eachshort, newly inserted, section of each weft thread which is in theprocess of being inserted, is beaten by a reed group of small widthalmost simultaneously with its insertion.

Thus, in order to solve the aforementioned problem with which theinvention is concerned, it must be possible for the fabric to beadvanced forwards in the region of th s small width, and in theremaining portion of the weaving width it must be fixed againstdisplacement in the warp direction. According to the invention this isachieved by causing the fabric which runs forward from the said fell, topass in the region immediately adjacent to the fell over at least onestationary surface having a convex curvature in the warp direction ofthe fabric, whereby the fabric is maintained in frictional engagementwith said surface as a result of the warp-wise tension in which it issubjected. Accordingly, those portions of the fell of the fabric onwhich tension is exerted through the still unwoven portions of the warpthreads running towards the fell on one side, and through the adjacentforwardly extending portion of the fabric on the other side, areimmobilized by the said frictional engagement against Warp- Wisedisplacement. However, such displacement is rendered possible byreduction or temporary suppression or suspension of such frictionalengagement for those portions of the fell at which a weft thread isbeing beaten up by members (hereinafter called reed groups) which atleast temporarily prevent the tension of the said unwoven warp threadportions from being transmitted to the fabric which extends forwardly ofthe fell.

Other features, objects and advantages of the invention will becomeapparent by reference to the following detailed description and drawingsin which:

FIGURE 1 is a schematic longitudinal sectional view through a waveWeaving loom equipped with a preferred embodiment of the apparatus;

FIGURE 2 is a fragmentary schematic top plan view of a portion of thewave weaving loom of FIGURE 1 equipped with the inventive apparatus forperforming the inventive method; and

FIGURE 3 is a partial perspective view showing the cloth deflectingmembers.

Turning attention now to the drawings, it will be understood that theillustrated wave weaving loom possesses a warp beam 11 from whichtravels a chain of warp threads which pass over a tension beam 12 andpartially through harnesses 13, partially through harnesses 14, whichdeflect the warp threads 10 upwardly and downwardly in order to formsheds 29. The chain of warp threads 10 pass from the harnesses 13, 14towards the fell line 15. As best recognized by inspecting FIGURE 2, theindividual harnesses 13, 13, 13", 13", etc. and 14, 14', 14", 14", etc.,in each instance, only extend over a small portion of the weaving width.They are displaced differently upwards and downwards in sucha mannerthat each shed only extends over a few, approximately 3, harness widthsand travels in the direction of the arrow 31, from the left to theright, across the weaving width. In each such travelling shed a weftthread is inserted by a shuttle 28 and behind such shuttle the insertedthread is beaten towards the fell line 15 by means of a group of reeds27 which extend across a fraction of the harness width. This fell line15 is formed at each location of the fabric width by a weft threadinserted in the last shed travelling through this location which isbeaten and interlaced by the warp threads crossing over this weft threadat the rear of this shed with respect to the weft inserting direction.

The fabric continuously produced at such fell line 15 moves over astationary support surface or rail 16 extending transversely over thefull fabric or cloth width. Support or deflecting rail 16 has adeflecting surface 15a which substantially possesses the form of asegment of a cylinder and exhibits grooves or ridges 32 extendingobliquely towards the outside from the rear towards the front (FIGURE2). In the illustrated embodiment, the fabric 20 is then guided beneatha likewise stationary cylindrical rod 17 extending over the same clothwidth and then is guided over a similar stationary rod 18. From thelatter the fabric moves further over an indexing or controller roll 21which rotates continuously during operation of the loom, then betweensuch indexing roll 21 and a cooperating contact roll 22, and over thelatter to the cloth beam 23 where it is wound up. Cloth beam 23 isdriven with a controlled rotational speed in such a manner that a clothpackage is formed thereon, the cloth possessing a uniform tension.

The deflecting or support rail 16 is stationarily seated upon a box orhousing 24 mounted on the frame 30 of the loom. This box 24 contains thedrive mechanism for the reed group 27 and the shuttles 28. Box 24 alsosupports both of the deflecting rollers or rods 17 and 18 through theagency of lateral support plates 19 connected to the aforesaid box. Rods17 and 18 engage by means of rectangular shaped end studs or lugs 17aand 18a respectively, with appropriate recesses 19a and 1% respectivelyprovided at the plates 19, and specifically, in such a manner that theycannot rotate about their corresponding lengthwise axis, yet are easilydemountable.

Slides 25 capable of moving to and fro between a forward and rearterminal position are guided in the box 24 and extend rearwardly beneaththe region in front of the harnesses 13 and 14 traversed by thetravelling sheds 29. At its rear end each slide member 25 carries one ofthe reed groups 27, the individual beat-up reeds of which, during eachposition of the slide, piercingly extend upwards between the warpthreads 10 and during movement of the slide 25 move to and fro between arear terminal position neighboring the harnesses 13 and 14 and a forwardterminal position directly neighboring the support rail 16 anddetermining the position of the fell line 15. A bifurcated 0r forkedmember 26 is seated upon each slide 25 in front of the reed group 27 andwhich together with the slide 25 neighboring the correspondingbifurcated member 26 receives a rib-shaped, bent, lower projection ofthe momentarily passing shuttle 31, whereby this shuttle in knownmanner, and for such reason not explained more fully, is forwardlydriven due to the relative movement of the neighboring slides 25. In myco-pending U.S. applications, Ser. No. 294,971 and Ser. No. 294,980,both filed July 15, 1963, there is disclosed mechanism for driving theshuttles across the weaving width at a wave weaving loom, and referencemay be readily had thereto. However, since details of the physicalstructure of such mechanism are not believed necessary for understandingthe teachings of the present invention no further description thereof ishere given.

During operation of the loom the indexing roll or beam 21 is driven at aspeed proportional to the travelling speed of the shuttles 28 andreciprocal to the desired weft thread density. This indexing roll 21strives to withdraw the warp chain 10 from the warp beam 11 via thefabric 20. This warp beam 11 is uniformly braked in known manner and,thus, maintains the tension of the unwoven portion of the warp chain 10constant. The fabric 20 extending forwardly from the fell line 15 isguided with such a deflection over the support rail 16 and the rods 17and 18 disposed directly in front of the fell line 15, that it is pulledwith a certain pressure against the corresponding surfaces of suchdeflecting elements 16, 17 and 18, on the one hand, by the tension ofthe u'nwoven portion of the warp threads 10 and, on the other hand, bythe tension in'iparted to it by the indexing roll 21. Due to thefriction of the fabric 20 at such surfaces and caused by such pressurethe fabric is fixedly held against displacement in the direction of thewarp, so that the tension of the indexing roll 21 upon the fabric 20,without anything further, will not bring about any displacement in thewarp direction. In fact, an equilibrium or balance condition appears ateach partial region of the fabric width, between the tension of thefabric generated by the indexing roll 21 the friction at the deflectingelements 16, 17 and 18, and the sum of the tensions of the unwovenportion of the warp thread 10 controlled by braking of the warp beam 11.This equilibrium condition remains as long as there i maintained thementioned tension of the warp thread chain 10 on the one hand, and thetension of the fabric 20 on the other hand.

Now, if a group of reeds 27 beats the weft thread, which occurs insuccession in each instance at those locations of the fell line 15 atwhich a corresponding section of weft thread has been inserted by atravelling shuttle 28, then this group of reeds 27 exerts a forwardlydirected force upon the fabric disposed in its region. As a result, thetension of the fabric at the fell line 15, in other words between thebeating reed group 27 and the support rail 16, in this region of thefabric width is temporarily reduced beneath the tension of thecorresponding unwoven war-p thread section 10 extending from the warpbeam 11 to the fell line 15. At the same time, there is also reduced thetension of the fabric in this width range travelling over the deflectingrollers 16, 17 and 18 and also the frictional force effective betweensuch members and the fabric. This results in the fact that after acertain displacement of the fell line 15 of the fabric by the reed group27 the tension imparted by the indexing or controller roll 21 to thefabric 20 is suflicient to forwardly displace the fabric to such anextent in the region determined by the width of the beating reed group27 as the reed group after impacting against the weft thread to bebeaten still moves further.

Since this weft thread is displaced by the reed group 27 to the samelocation previously occupied by the last weft thread beaten by it, andsince further movement of the fabric 20 at the side of the indexing roll21 is prevented by the defiecting members 16, 17 and 18, the newlyinserted weft thread is only displaced forwardly through a weft threaddivision of the fabric 20.

This feed is not hindered on account of its minuteness by the fact thatat both neighboring regions of the fabric width, at which other reedgroups are effective, at the same moment there does not appear any feedof the fabric 20. This difference in feed is momentarily compensated dueto the mutual displaceability of the threads also in the finished fabricand due to its elasticity; moreover, it only occurs at the forward flankof the relevant reed group 27 with respect to the direction of travel ofthe shuttles 28, since the reed groups in this direction of travelsuccessively perform a beating action and each thus forwardly displacesthe Weft thread to the same extent as it has been forwardly displaced inthe previous moment by the reed group located at its rear flank.

The elasticity of the fabric 20 also makes it possible to continuouslyrotate the indexing or controller roll 21 notwithstanding the fact thatthe feed movement of the fabric 20 is intermittent a each location ofits width.

When each reed group 27 moves back again, the weft thread section whichhas been displaced forwardly by that reed group and which now forms partof the fell line 15 at that place, remains at the location up to whichit has been displaced. This is so because at the same time as thetension prevailing in the still unwoven portions of the respective warpthreads again becomes effective on the fell of the fabric rather than onthe receding reed group 27, the tension placed upon the fabric by therotation of the indexing beam 21 again assumes its former value due tothe braking effect exerted on the warp beam 11. Since this tensionprevails in the fabric 20 both at the fell 15 thereof and at each of thedeflecting members 16, 17 and 18, the friction caused by the engagementof the fabric with the surfaces of these members becomes so high thatthe tension placed upon the fabric 20 by the indexing beam 21 no longeris large enough to advance the fabric in the region of its fell 15.

The outcome of this is that a certain average tension appears at thefabric 20 between the group of deflecting members 16, 17 and 18 and theindexing roll 21 which is dependent upon, the tension of the stillunwoven warp thread section 10 maintained by braking the warp beam 11,the frictional conditions prevailing at the mentioned deflectingmembers, and the angular velocity of the indexing roll 21. This tensionof the fabric 21} can be greater or smaller than the correspondingtension of the warp thread section 10. It determines at which momentduring heating by a reed group 27 displacement of the fabric in thedegion of the fell line 15 begins and through which path this fabricthus passes until the reed group 27 has reached its forward terminalposition, that is, how large will be the weft thread distribution of thefabric. With a given tension of the unwoven warp thread section 10,given friction at the deflecting members 16, 17 and 18, and for instancewith large feed of the fabric by the indexing roll 21, the tension ofthe fabric 26 is high since, then, the fabric is more pro-stressed fromone "beat to the next of each reed group 27. Upon beating the weftthread a smaller unloading of the fabric at the fell line 15 is thennecessary until the friction at the deflecting members is overcome bythe fabric tension appearing between such and the indexing beam 21, andthe feed movement begins by means of the respective reed group. The feedpath. in other words, the weft thread distribution is then larger, withthe result that it comes into coincidence with the larger peripheralspeed of the indexing roll 21.

In order to be able to change the degree of deflection or deviation ofthe fabric 20 at the deflecting or support members 16, 17 and 18 and,thus, to change the friction between the fabric and such deflectingmembers, it is possible to exchange each of both deflecting rods 17 and18 for one of a different diameter. It is also remarked that thepossibility exists of completely removing the defleeting rod 18 in orderto reduce the Wrap around angle of the fabric at the rod 17.

In order that the diameter of the rods 17 and 18 can be maintainedsmall, these rods are preferably manufactured so as to have a slightlongitudinal curvature in the absence of external forces as shown inFIGURE 3, in such manner that when they will be subjected to the actionof the expected tension of the fabric, their axes will be deflected toextend approximately straight from one side plate 19 to the other. Asshown in FIGURE 3,

\ in its undeflected state the rod 17 is curved substantially downwardswhile rod 18- is curved both slightly to the rear and in a largermeasure upwards since, as can best be seen in FIGURE 1, the fabric 20passes under the rod 17 and over the rear upper side of the rod 18. Whentension is exerted on the fabric 20 by the indexing roll 21, the fabricexerts an upward force on the rod 17 and a downward and forward force onthe rod 18, whereby the rods are deflected until their axes aresubstantially straight. In this manner it is possible to obtain aprecise operation of the apparatus with large weaving Widths, withoutrequiring quite heavy rod profiles or sections.

The rods 17 and 18 are provided at their ends with flat extensions 17a,18a, respectively, which engage corresponding guide slots 19a, 19b, inthe side plates 19. The

guide slots 19a which receive the extensions 17a of rod 17 arehorizontal while those 1% which receive the extensions 18a of rod 18 arevertical. Accordingly, the rod 17 is displaceable horizontally and therod 18 is displaceable vertically each in the corresponding slots; theflat extensions 17a, 18a prevent the rods 7 and 18 from rotating intheir slots. The position of each rod extension 17a, 18a in therespective slot 19a, 19b is determined by an adjustment screw 40 screwedthrough an abutment 190 formed on the side plate 19. By displacing therod extensions 17a, 18a in their slots, the positions of the rods 17 canbe altered so as to vary the angles at which the fabric 20 runs off thedeflecting rail 16 and onto and off the rods 17 and 18. This permitsmodifying the friction effect as desired.

The fluting or notching 32 0f the support rail 16 extending obliquely orat an inclination from the inside to the outside in the direction oftravel of the fabric 29 causes a traction or tension to be exerted intransverse direction i.e. across the width, upon the fabric directly atthe fell line 15, so that such tends to pull together as little aspossible after insertion and beating of the weft thread. A correspondingfluting could also be provided at the lower portion of the deflectingroller 17, and, if desired, at the rear and upper sides of thedeflecting roller 18, although it is hardly there necessary.

The deflecting or sup-port rail 16 provides the further advantage withregard to shed formation that due to it the elevational position of thefell line 15 is fixed.

It would also be possible to mount this support rail 16, or a deflectingrod provided in place of such, in a manner that the fabric, beginningfrom the fell line, moves beneath it and then over the next deflectingelement or rod 17. The exemplary arrangement shown in the drawing hasthe advantage that the fell line 15 is readiiy accessible and visible.

, The foregoing detailed description has been given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom, as modifications will be obvious to those skilled in the art.

I claim:

1. A method of operating a wave weaving loom having a braked warp beamand a tension bar to apply tension to the warp threads, harnesses toform sheds to progressively define a fell line and an indexing roll toapply tension to the progressively formed fabric wherein the movement ofthe fell line is controlled to form a fabric free of warp-Wise runningirregularities, comprising guiding the fabric formed at the fell lineand extending forwardly at the region neighboring such fell line over atleast one stationary convex guiding surface in the direction of travelof the warp threads and fabric, subjecting each portion of the fabricbearing upon such surface to frictional engagement therewith dependingon the tension transmitted to said portion of the fabric by the stillunwoven portions of said warp threads extending into said portionopposing the feed of the fabric by said indexing roll, said frictionalengagement preventing warp-wise displacement of said portion, andsuccessively beating respective finite regions of the fell line toreduce said force opposing the feed of the fabric forwardly of said fellline to reduce the action of said frictional engagement at each of saidrespective finite regions to enable forward feed of the latter.

2. Method according to claim 1 including the step of exerting atransverse extending pulling force on the fabric extending forwardly ofthe fell line in the region of said stationary convex surface.

3. Method according to claim 1 including the step of additionallydeflecting the fabric extending forwardly of the fell line over a secondconvex guiding surface.

4. Method according to claim 3 wherein the fabric extending forwardly ofthe fell line is deflected over both of said convex guiding surfacescurved in opposite directions.

5. Method according to claim 3 wherein said stationary convex surfaceclosest to the fell line is convex in a substantially upward directionand said second surface follows said first mentioned surface in thedirection of travel of the warp and fabric and is convex in asubstantially downward direction.

6. A method of operating a wave weaving loom having a braked warp beamand a tension bar to apply tension to the warp threads, harnesses toform sheds to progressively define a fell line and an indexing roll toapply tension to the progressively formed fabric wherein the movement ofthe fell line is controlled to form a fabric free of warp-wise runningirregularities, comprising guiding the fabric formed at the fell lineand extending forwardly at the region neighboring such fell line over atleast one stationary convex guiding surface in the direction of travelof the Warp threads and fabric, subjecting each portion of the fabricbearing upon such surface to frictional engagement therewith dependingon the tension transmitted to said portion of the fabric by the stillunwoven portions of said warp threads extending into said portionopposing the feed of the fabric by said indexing roll, said frictionalengagement preventing warp-wise displacement of said portion,introducing a weft thread at the region of the fell line, andsuccessively beating respective finite regions of the fell line toreduce said force opposing the feed of the fabric forwardly of said fellline to reduce the action of said frictional engagement at each of saidrespective finite regions to enable forward feed of the latter.

7. In combination with a wave weaving loom for weaving a woven fabrichaving a braked warp beam and a tension bar to apply tension to thewar-p threads, harnesses to form sheds to progressively define a fellline and an indexing roll to apply tension to the progressively formedfabric, an apparatus to control the movement of the fell line to formsaid fabric free of warp-wise extending irregnlarities comprising atleast one stationary segment shaped deflecting member positioned tocooperate with the woven fabric formed at the fell line and extendingforwardly of the fell line, said deflecting member including a sup-portconvex guiding surface extending in the direction of the warp of saidfabric.

8. The combination set forth in claim 7 wherein said deflecting memberis constructed in the form of a rail which extends substantially acrossthe full fabric width.

9. The combination set forth in claim 7 including at least oneadditional adjustable deflecting member arranged forwardly of saidstationary deflecting member in the direction of the warp and fabrictravel, both of said deflecting members being arranged in substantialparallelism with respect to one another, said additional deflectingmember incorporating a support convex guiding surface cooperating withthe fabric passing thereover, said support surfaces of both deflectingmembers extending in opposite directions.

10. The combination set forth in claim 7 wherein said support surfacefaces upwardly and possesses an inclination which increases downwardlyin the direction of travel of the woven fabric to downwardly deflect thefabric passing from the fell line over said stationary deflectingmember.

11. The combination defined in claim 10 including an additionaladjustable deflecting member arranged in the direction of travel of thefabric forwardly of and substantially parallel to said stationarydeflecting member, said additional deflecting member possessing asupport convex guiding surface extending substantially downwardly toupwardly deflect the fabric travelling over said last mentioned supportsurface coming from said stationary deflecting member.

12. The combination set forth in claim 7 wherein said support surface ofsaid stationary deflecting member is provided with fluting extending atan inclination from the inside towards the outside in the direction oftravel of the woven fabric.

13. The combination as set forth in claim 7 including at least a seconddetachable and exchangeab-ly mounted deflecting member.

14. The combination as set forth in claim 7 including at least a seconddeflecting member having a support convex guiding surface, and means foradjustably mounting said second deflecting member substantiallytransversely with respect to its support surface.

15. The combination as set forth in claim 7 wherein said support surfaceof said stationary deflecting member in the unloaded condition possessesa convex lengthwise profile so that upon loading of said stationarydeflecting member by the warp tension of the woven fabric it is bent sothat the curvature of said convex lengthwise profile is at leastpartially reduced.

References Cited OTHER REFERENCES German application 1,072,569,Haberhauer,

pub. December 31, 1959.

HENRY S. JAUDON, Primary Examiner.

